The present invention relates to a scanner system, and more particularly to a scanner system which is operable either in a mode where a scanner is moved on an original, or in another mode where an original is fed by a sheet feeder
Conventionally, a scanner system having a scanner which is provided with a line sensor extending in a predetermined direction (i.e., a main scanning direction) has been known. The scanner is positioned on an original, and then moved in a direction (i.e., an auxiliary direction) which is perpendicular to the extending direction of the line sensor to scan a two-dimensional area of the original. The scanner system may further be provided with an auxiliary device which enables the scanner system to feed the original in the auxiliary direction. In such a system, instead of moving the scanner, by coupling the auxiliary device to the scanner, the original is automatically fed and scanned.
In the scanner system having the automatic sheet feed function, operation sequences (i.e., operation programs) when the scanner is moved on the original and when the original is fed by the sheet feed function should be changed. In particular, if the auxiliary device to be coupled to the scanner is provided with a sheet feeding mechanism which can operate independently of the scanner, the sheet feeding mechanism should be controlled by the scanner so that the sheet feeding operation is executed synchronously with the scanning operation of the scanner. For this purpose, both the scanner and the auxiliary device should be constituted to communicate with each other, i.e., interfaces and communication ports should be provided. Further, a sensor should be provided to detect whether the auxiliary device is coupled to the scanner. Such a constitution prevents the scanner system from being formed compact and inexpensive.
If the sheet feeding mechanism is of a mechanism utilizing driving force of the scanner, communication between the auxiliary device and the scanner is unnecessary, and accordingly the interfaces and communication ports may be eliminated. However, also in this case, a sensor for detecting whether the auxiliary device is coupled to the scanner should be provided. A micro-switch is generally used as the sensor for detecting coupling of the auxiliary device to the scanner, and such a constitution still requires certain space.
Recently, as a line sensor, a so-called CIS (Contact Image Sensor) has been developed and widely used for scanners. The CIS has a plurality of CCD elements arranged in a line, gradient index lens array, and a light source. The CIS is made to contact an original document to be scanned. The document is illuminated by the light source, and reflected light is directed to the CCD elements via the gradient index lens array. The CCD elements accumulate electric charges in accordance with received light amount. Because of its structure, the scanner employing the CIS can be made compact. However, if the auxiliary device having a sheet feeding mechanism is to be coupled to the scanner, the scanner should be constituted to have a sufficient room for receiving the auxiliary device. Further, each of the scanner and the auxiliary device should be formed to have a shape which ensures, without malfunction, the detection of the auxiliary device. Such a constitution prevents the scanner system from being made compact, and increases manufacturing cost.
It is therefore an object of the invention to provide an improved scanner system, which is operable in a mode where the scanner is moved on an original and the image is scanned and in another mode where an auxiliary device is coupled to the scanner and the original is automatically fed and scanned, the operation mode of which can be detected without error, with a simple and compact structure.
For the above object, there is provided a scanner system which is provided with: a scanner provided with an image sensor; and a sheet feed adapter detachably coupled to the scanner. A predetermined surface of the sheet feed adapter faces the image sensor when the sheet feed adapter is coupled to the scanner. The scanner is operable in a hand scan mode when the sheet feed adapter is detached from the scanner, and in a sheet through mode when the sheet feed adapter is coupled to the scanner. In the sheet through mode, an original to be scanned is automatically fed between the predetermined surface and the image sensor. A predetermined image is formed on the predetermined surface of the sheet feed adapter, and the scanner comprises a judging system that judges that the sheet feed adapter is coupled to the scanner only when the image sensor scans the predetermined image on the predetermined surface of the sheet feed adapter.
Since the image sensor is used for detecting the sheet feed adapter, additional sensor such as a micro-switch is not necessary. Thus, the system can be made compact and simple. Further, since the judging system judges that the sheet feed adapter is coupled only when the predetermined image is detected, the operation mode can be detected without error.
In particular, the image scanner may be provided with a line image sensor extending in a predetermined direction. In this case, the line image sensor may have an effective scanning area which contributes to scanning of image on an original and at least one non-effective scanning area which does not contribute to scanning of the image on the original, and preferably, the predetermined image may be formed on the predetermined surface at a portion facing the noncontributing area.
Optionally, each end portion of the line image sensor is used as the non-effective scanning area and an area between the non-effective scanning areas is used as the effective scanning area.
The predetermined image may include a monochromatic image, a color image, a predetermined pattern, or a combination thereof.
Optionally, a chart used for white level compensation of the line image sensor is formed on the predetermined surface of the sheet feed adapter, at a portion facing the effective scanning area.
Further optionally, the scanner may be provided with: a plurality of rollers rotatable about axes which are parallel to the extending direction of the line image sensor; and a driver that drives the plurality of rollers to rotate.
Thus, when the sheet feed adapter is detached, the scanner functions as a self-running scanner, while when the sheet feed adapter is coupled, the driving force of the self-running scanner can be used for automatic sheet feeding.
Preferably, the sheet feed adapter may have a plurality of freely rotatable rollers. The freely rotatable rollers are arranged at positions corresponding to the plurality of rollers of the scanner when the sheet feed adapter is coupled to the scanner. The plurality of freely rotatable rollers may be biased towards the plurality of rollers of the scanner when the sheet feed adapter is coupled to the scanner so that the plurality of freely rotatable rollers are driven by the plurality of rollers of the scanner to rotate.
Since the sheet feed adapter does not have a power source, and utilizes the driving force of the scanner for feeding the original, the sheet feed adapter can be made simple and compact.
Further optionally, the line image sensor has an image scanning surface which faces an original to be scanned, and a paper sensor for detecting presence or absence of a paper is provided on an upstream side of the image scanning surface, along a direction in which the original is fed when the sheet feed adapter is coupled to the scanner.
Furthermore, a controller may be provided for controlling the driver to rotate the plurality of rollers, when the paper sensor detects presence of the original, so that a leading edge of the original reaches the image scanning surface.
According to another aspect of the invention, there is provided a scanner system, which is provided with: a self-running scanner provided with a self-running mechanism; and a sheet feed adapter to be coupled onto an image scanning surface of the self-running scanner, driving force of the self-running mechanism of the self-running scanner feeding an original when the sheet feed adapter is coupled to the scanner, a predetermined image being formed on a surface facing the image scanning surface of the self-running scanner for indicating that the sheet feed adapter is coupled to the scanner.
Optionally, the scanner may include a line image sensor, scanning area of the line image sensor including a first area to be used for scanning an image on an original, and a second area which is used for scanning the image formed on the sheet feed adapter.